Bottle base



FIG. 1 is a perspective view of a bottle base showing my new design assembly;

FIG. 2 is a side elevation view thereof, the opposing side, rear and front elevation views being identical;

FIG. 3 is a top plan view thereof;

FIG. 4 is a bottom plan view thereof; and,

FIG. 5 is a cross sectional view, taken along lines 5-5 of FIG. 3.

The broken lines in the drawings showing the bottle base illustrate the portions of the bottle base that form no part of the claimed design. 

CLAIM The ornamental design for a bottle base, as shown and described. 